任务要求:利用PictureBox控件设计一个图片查看器

好的，我可以帮你设计一个基于PictureBox控件的图片查看器。首先，你需要在窗体上添加一个PictureBox控件，它将用于显示图片。然后，你可以添加一些按钮来实现图片的打开、保存、缩放等功能。

下面是一个简单的示例代码，可以帮助你开始编写这个图片查看器：

public partial class Form1 : Form
{
    public Form1()
    {
        InitializeComponent();
    }

    private void openToolStripMenuItem_Click(object sender, EventArgs e)
    {
        OpenFileDialog openFileDialog = new OpenFileDialog();

        openFileDialog.Filter = "Image Files (*.jpg; *.jpeg; *.gif; *.bmp)|*.jpg; *.jpeg; *.gif; *.bmp";

        if (openFileDialog.ShowDialog() == DialogResult.OK)
        {
            pictureBox1.Image = new Bitmap(openFileDialog.FileName);
            pictureBox1.SizeMode = PictureBoxSizeMode.Zoom;
        }
    }

    private void saveToolStripMenuItem_Click(object sender, EventArgs e)
    {
        SaveFileDialog saveFileDialog = new SaveFileDialog();

        saveFileDialog.Filter = "JPEG Image|*.jpg|Bitmap Image|*.bmp|Gif Image|*.gif";

        if (saveFileDialog.ShowDialog() == DialogResult.OK)
        {
            switch (saveFileDialog.FilterIndex)
            {
                case 1:
                    pictureBox1.Image.Save(saveFileDialog.FileName, System.Drawing.Imaging.ImageFormat.Jpeg);
                    break;
                case 2:
                    pictureBox1.Image.Save(saveFileDialog.FileName, System.Drawing.Imaging.ImageFormat.Bmp);
                    break;
                case 3:
                    pictureBox1.Image.Save(saveFileDialog.FileName, System.Drawing.Imaging.ImageFormat.Gif);
                    break;
            }
        }
    }

    private void zoomInToolStripMenuItem_Click(object sender, EventArgs e)
    {
        pictureBox1.Width += 10;
        pictureBox1.Height += 10;
    }

    private void zoomOutToolStripMenuItem_Click(object sender, EventArgs e)
    {
        pictureBox1.Width -= 10;
        pictureBox1.Height -= 10;
    }
}

这个示例代码实现了打开、保存、缩放等功能。你可以根据自己的需求来添加更多的功能。希望这能帮到你！